A letter signed by 40 of the world�s leading artists, including Lucian Freud, Damien Hirst, David Hockney, Douglas Gordon and Alison Watt, has been delivered to Prime Minister Gordon Brown, urging him to back the campaign to keep Titian�s Diana and Actaeon in the UK.

A letter signed by 40 of the world's leading artists, including Lucian Freud, Damien Hirst, David Hockney, Douglas Gordon and Alison Watt, has been delivered to Prime Minister Gordon Brown, urging him to back the campaign to keep Titian's Diana and Actaeon in the UK.

The owner of the painting, the Duke of Sutherland, has offered it to the National Galleries of Scotland and the National Gallery in London for £50m, and the two institutions have until the end of next month to raise the money.

The often-controversial contemporary artist, Tracey Emin, delivered the letter to 10 Downing Street yesterday.

The letter expresses the artists' support for the National Gallery and National Galleries of Scotland joint campaign to save Diana and Actaeon, and its sister painting Diana and Callisto, for the nation.

It states: "The paintings, which are among the finest works in private hands in the world, have been in Britain for more than two centuries and on continuous public view at the National Gallery of Scotland since the collection was placed there in 1945, inspiring generations of visitors.

"The high reputation currently being enjoyed by British art, both at home and abroad, depends on the extraordinary quality and depth of our national collections, which have always been, and remain, a constant stimulus to contemporary artists.

"We also believe that in challenging times the heritage of the past and the art of the present are more important than ever."

The list of signatories to the letter also includes leading figures in the art world such as Peter Blake, Grayson Perry, Ron Mueck, Richard Demarco, and Frank Auerbach, among many others.

So far, with a deadline of December 31 looming, only £1m has been publicly pledged to keep the Titian painting hanging in the National Gallery of Scotland (NGS) in Edinburgh.

The Art Fund - the UK's leading independent art charity - has given the grant, the largest for a single work of art in the fund's 105-year history.

Next week, the galleries will meet the National Heritage Memorial Fund about the possibilities of another grant.

Yesterday, a spokeswoman for the Department of Culture, Media and Sport in Westminster said: "We fully support the campaign to raise money to keep the picture permanently in the UK but it is too early to say what, if any, support the government can offer in cash terms, particularly in the current difficult financial climate."

The Scottish Government has also expressed support for the campaign but has yet to detail any funds it may provide.

Last week the leading German artist Gerhard Richter, opening a new retrospective of his work at the NGS, said: "It is part of our culture in Europe and it should stay where it is."

He went on to say that foreign-based collectors would be likely to snap up the painting if it appeared on the open market.

The painting has been on loan to Scotland since 1945 as part of the Bridgewater Collection, which also includes other works by Titian, three paintings by Raphael, a work by Rembrandt and the Seven Sacraments by Poussin.

The duke has offered Diana and Actaeon to the NGS for £50m as the first part of a deal that will help guarantee that the rest of the works remain in Scotland for at least another generation.

A £50m price tag for its sister painting, Diana and Callisto, also needs to be raised by 2012. If acquired, both paintings will then go on a rotating display between London and Edinburgh, spending five years at a time in each location. The £50m price for Diana and Actaeon has been described by gallery sources as roughly one-third of the amount it would reach if sold at auction.

It is understood that by the end of this month it will be clear if the money is likely to be raised before the December 31 deadline.